A motion generating system for propelling and/or lifting a craft exploiting explosive and implosive processes, whereby a propulsive or lifting force on the craft arises from two sources: generation of a stream of fluids which imparts thrust to the craft; and generation of zones of reduced pressure and density in front of and above the craft allowing the craft to be thrust forward and lifted by ambient pressure on the rear and underside of the craft. Furthermore, reduction of fluid density in front of the craft results in a reduction of frontal drag allowing the attainment of higher speeds. The motion generating system may have other applications; for example, the motion generating system may be used to propel a stream of liquid in the manner of a pump.